The point about Nebula having an exclusivity clause feels pretty incorrect. I haven't seen a contract, obviously, but tons of videos uploaded on Nebula are also available on YouTube. There are some videos labeled "Nebula Originals" and I would imagine those are exclusive, but that's a fraction of the content on most channels, at least from what I've seen.
He says in the video that YouTube is the only exception to the exclusivity clause, meaning the couldn't also publish to Float Plane or other similar platforms.